This invention relates to coated cookware having a heat-stable multi-layer nonstick coating.
In modern cookware coatings, it has been found desirable to provide a sparkling appearance. However, sooner or later, food stains appear in most cookware coatings. These stains generally have a brown color and are formed by pyrolysis of particles of food, oil or other materials which penetrate into the more-or-less porous outer layers of the coating. This phenomenon occurs with most types of cookware coating, including coatings based on polytetrafluoroethylene (PTFE).
The problem of staining becomes more acute when the temperature profile across the face of the cooking surface is not uniform. This occurs particularly in cookware heated by an electrical resistance element in the shape of a pattern imbedded in or against the back of the cookware, i.e., the surface opposite that on which the coating system is applied. This staining phenomenon takes the form of a brown line following the pattern of the heating element.
It would be desirable to be able to coat electric cookware in such a way that no conspicuous stained pattern develops during use of the cookware.